Z4 2.0 2008 Odd Noise/Vibration

[fr45er]

Hello, I have a 2.0 z4 (2008)

Whilst cruising at motorway speeds at around 75mph 3k RPM and above I get a slight knocking feeling through the gearstick that is a lower frequency than the engine, which is related to the engine RPM and not speed. I can feel it at slower speeds when above 3k RPM also. I have had it into the dealer I bought it from for the day but they couldnt detect it, probably because they didnt take the car out on the road...

Any thoughts?

(I have posted this on other z4 forums, but didnt really get anywhere)

 

[Spikey]

Can you only feel the knocking if you hold the gear lever? Or do you see it visibly shaking?

Or worse do you feel the knocking via seat / footwell etc. ? :roundel:

 

[fr45er]

Only when I hold the gearstick.

 

[Spikey]

Surely that's just normal road vibration then ?

Next time Im out I will see if I get same

 

[fr45er]

Definately doesnt feel normal, its at a different frequency to the engine but is still proportional to the RPM. Booked it in to the dealer for next week anyway just to get it checked out, my coolant light was on for about a minute also, so can get them to check it at the same time